How do I delay a button performing an action by a certain timeframe, if the button wasn't pressed again in that timeframe?

Question

Sorry for the terrible title, I am bad at describing these things.

I am building a metronome and have a (-) UI button that decreases the tempo by 1, and a (+) UI button that increases the tempo by 1.

My problem currently is that whenever I press either buttons, the metronome restarts itself since there's a new tempo, and plays immediately. So if you press the (-) button 10 times in a row, each time you press it you hear the initial metronome "beep".

I would like my app to do the following:

When the user clicks either (-) or (+) buttons, wait for 200 milliseconds
IF the user didn't click the buttons again in that timeframe, play the metronome
If the user DID click the button again, don't play the metronome, repeat the process: wait 200 milliseconds, if no click was made play the metronome, etc

The end result would be that if I'm at 100 bpm and I repeatedly press the (+) button 20 times until I am at 120 bpm, the metronome wouldn't start playing until I am done tapping.

How do I go about implementing this? Thank you!

It sounds like you just described the algorithm you should write to implement what you want it to do. Which part do you not know how to do? — user132278, Mar 17 '16 at 00:28
I am new to android and Java development, so it's a bit overwhelming. I am not sure what would be the best/correct way to implement it. — A. Quest, Mar 17 '16 at 01:24

Rafael Lucena · Answer 1 · 2016-03-17T13:11:12.053

0

If you want a delay between the action and the effect, there are several ways you can achieve it. This is one.

 private boolean pressedAction = false;

@override
public void onClick(View v) {

    if (pressedAction) return;
    pressedAction = true;
    new Thread(new Runnable(
        @override
        public void run() {

            try {
                Thread.sleep(200); // 200 miliseconds
            } catch (Exception e) {}

            // Update views or do work (program logic)

            pressedAction = false;
        }
    }

}

Then, the metronome logic is your bussiness.

edited Mar 17 '16 at 13:11

answered Mar 17 '16 at 00:47

Rafael Lucena

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9

Thanks for the answer. Unless I misunderstood you, I don't think this is what I'm looking for. This seems like a simple delay, but what I'm looking for is a bit more complicated: if the user presses the button 20 times in a row, I want only the very last tap to execute the function - the first 19 taps should do nothing. In this case, if I press the button 20 times in a row, the function still executes 20 times, except with a delay. I hope that makes it clearer. Thanks – A. Quest Mar 17 '16 at 01:23

score 0 · Answer 2 · edited May 23 '17 at 12:31

Declare and instantiate the below in your activity:

     private Handler timeoutHandler = new Handler();
     private Runnable delayStartThread = new Runnable() {
                public void run() {
                    startMetronome();
                }
            };

Then insert the below code block in your onClickListener for both + and - buttons:

    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            timeoutHandler.removeCallbacks(delayStartThread);
            tempoOfMetronome++; //tempoOfMetronome--; for decrease button
            stopMetronome();
            timeoutHandler.postDelayed(delayStartThread, 200);
        }
    });

For more details on how the code works, refer the below links for examples (I used these examples to formulate the answer):

Android: clicking TWICE the back button to exit activity - How to use handler.postDelayed()
How to cancel handler.postDelayed? - How to cancel handler.postDelayed()

You should also look at the Android documentation for those methods.

How do I delay a button performing an action by a certain timeframe, if the button wasn't pressed again in that timeframe?

2 Answers2